User`s guide

1 Data Processing
You must import your frequency-response data into the MATLAB workspace
as the following variables:
• In System Identification Tool GUI or MATLAB Command Window,
represent complex-v alued G(e
iw
).
For single-input single-output (SISO) systems, the frequency function is
a column vector.
For a data set with N
u
inputs, N
y
outputs, and N
f
frequencies, the frequency
function is an N
y
-by-N
u
-by-N
f
array.
• In System Identifi cation Tool GUI only, represent amplitude
G
and phase
shift
ϕ=argG
.
For single-input single-output (SISO ) systems, the amplitude and the
phasemusteachbeacolumnvector.
For a data set with N
u
inputs, N
y
outputs, and N
f
frequen c ies, the amplitude
and the phase must each be an N
y
-by-N
u
-by-N
f
array.
• Freq uency val ues mu st be a column vector .
For more information about importing data into the M ATL AB workspace, see
the MATLAB documentation.
After you impo rt data into the MATLAB w orkspace, you can import it into
the System Identification Tool GUI or create a data object for w orking at the
command line. F or more information about importing data into the GUI, see
“Importing Frequency-Response D ata into the GUI” on page 1-21. To learn
more about creating a data object, see “Representing Frequency-Response
Data Using idfrd Objects” on page 1-67.
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